1. Field of the Invention
The present invention relates to a coating and developing method of and a coating and a developing system for coating a surface of a substrate with a liquid resist film and processing the substrate coated with the resist film processed by an immersion exposure process, and a storage medium storing programs for accomplishing the coating and developing method.
2. Description of the Related Art
Photolithography applied to fabricating a semiconductor device includes a series of processes for forming a resist film on, for example, a semiconductor wafer (hereinafter, referred to simply as “wafer”), exposing the resist film through a photomask, and developing the exposed resist film to form a desired resist pattern on the wafer.
An exposure method coats a surface of a substrate with a liquid film and exposes the surface through the liquid film. This exposure method will be referred to as “immersion exposure method”. Such an exposure method is disclosed in JP-A 2005-175079 (Patent document 1). As shown in FIG. 10, an exposure device 1 is provided with a lens 10 on a central part of its lower end, a pouring opening 11 and a suction hole 12. Pure water is poured onto the surface of a wafer W and the pure water poured onto the wafer W is recovered through the suction hole 12 to form a liquid film (pure water film) in the gap between the lens 10 and the surface of the wafer W. A resist film formed on the surface of the wafer W is exposed to light through the liquid film. Then, as shown in FIG. 11, the exposure device 1 is moved horizontally to position the exposure device 1 at the next shot area 13 and an exposure cycle for exposing the shot area 13 to light is repeated to transfer the predetermined circuit pattern successively to shot areas 13 in the surface of the wafer W. In FIG. 11, the shot areas 13 are exaggerated.
Studies have been made to suppress the dissolution of a resist film formed on a surface of a wafer W and to make the liquid layer used for immersion exposure difficult to remain on the surface of the wafer W by forming a water-repellent protective film on the surface of the wafer W before forming the resist film on the surface of the wafer W and subjecting the wafer W to immersion exposure.
A film removing method mentioned in JP-A 2005-183709 (Patent document 2) removes a water-repellent protective film formed on a surface of a wafer W by a developing system after subjecting the wafer W to a heating process by a heating device.
When the wafer W having the protective film formed on the resist film formed on the surface of the wafer W is subjected to the heating process, the resist film coated with the protective film is not exposed to a hot atmosphere in the heating device. Consequently, substances contained in the resist film and those existing on the surface of the resist film segregate and the distribution of substances in the resist film becomes nonuniform. When the resist film of a nonuniform quality is processed by a developing process, defects are produced in the resist film and the controllability of the width of lines forming a resist pattern is unsatisfactory.